1. Field of the Invention
The present invention relates to a hand-held blind rivet riveting tool. More specifically, the present invention relates to a hand-held blind rivet riveting tool that includes a housing, a drawing element that can be displaced in a drawing direction relative to the housing, a first grip lever that is pivotable about a first pivot point relative to the housing, and a second grip lever connected to the housing.
2. Discussion of the Related Art
Conventionally, to set a blind rivet, the blind rivet's rivet shank is first introduced into an opening of a blind rivet tool. The rivet shank is then drawn into the tool. During this movement, the rivet shank is deformed on the side of the blind rivet that cannot be seen (i.e., the side within the riveting tool). The rivet pin eventually breaks, thereby resulting in the blind rivet being set. The procedure to set a blind rivet nut is similar to that of a blind rivet except that a drawing pin is usually screwed into the blind rivet nut. The drawing pin is not broken, After the blind rivet nut is set, the drawing pin is unscrewed from the now set blind rivet nut.
When setting either a blind rivet or a blind rivet nut, a certain tensile force must be applied to deform the rivet shank or rivet pin to produce the closing head. The blind rivet or blind rivet nut is inserted into the blind rivet riveting tool until the rivet head butts against an abutment of the tool. The rivet shank or pin is gripped by a drawing element within the tool. Grip levers of the tool are then moved toward one another, causing the drawing element and, therefore, the gripped rivet pin or shank to move away from the abutment to set the blind rivet or blind rivet nut.
Blind rivet riveting tools of the type described above are known from, for example, German Reference No. DE 31 24 648 A1. The grip lever in the German '648 reference is actuated by a user's thumb or the ball of the thumb. The grip lever is a single-armed lever which acts on a two-armed lever. A drawing element is fastened at the top of the two-armed lever. The single-armed lever and the two-armed lever are used to maintain the force applied by the user's hand relatively small.
U.S. Pat. No. 4,932,638 to Chen discloses a tool for setting expansion bolts. A grip lever acts on clamping plates, which are arranged around a drawing element. When the grip lever is actuated, one of the clamping plates wedges on the drawing element. Further movement of the grip lever causes the drawing element to be displaced.
German Reference No. DD 130 757 A1 discloses a blind rivet riveting tool that has an articulated head. The articulated head is disposed between the ends of two levers that form hand grips, thereby achieving a relatively high degree of leverage.
In all of these conventional tools, the setting of blind rivets and blind rivet nuts by hand is relatively laborious. If the grip width is enlarged so that the drawing element has a sufficient displacement to set a blind rivet, then it is often no longer possible for the handles to be actuated using only one hand. This problem is reduced somewhat by German Reference No. DE 31 24 648 A1 because it permits multiple ratcheting actuations of the grip lever during a single setting operation. But, because of the considerable friction losses produced by the large number of deflections, only some of the hand force applied by the user is used to set the blind rivet.
The tool disclosed in U.S. Pat. No. 4,932,638 to Chen loses some of the hand force to the displacement of the clamping plate to wedge the plate on the drawing element. Additionally, while the tool described in the '638 patent also permits multiple actuations of the grip levers in a single setting operation, this tool is not easy to use.
Accordingly, it is an object of the present invention to simplify the handling of a blind rivet riveting tool.